Nicola Sturgeon has been accused of a “cynical” attempt to deflect attention from Scotland’s multi-billion pound deficit by claiming Brexit could cost the country billions every year.

The Scottish Government analysis of the cost of leaving the EU was released 24 hours before official figures that could reveal the biggest ever gap between what Scotland raises in taxes and its spending money from Westminster.

Opponents said the First Minister was trying to “muddy the waters” and boost the case for another independence referendum while ignoring Scotland’s multi-billion pound “Union dividend”.

One pro-Union group said Scotland's deficit for 2015-16 was expected to be even higher than the £15 billion figure revealed in March, when opposition parties said the data had devastated the case for separation.

The row followed the release of a government analysis of Brexit that claimed the country's GDP could be between £1.7 billion and £11.2 billion lower per year by 2030.

It said Brexit would hit Scottish tax revenues by up to £3.7 billion annually, and Ms Sturgeon claimed the figures were evidence of the need to protect Scotland’s relationship with Europe.

She also revealed plans to appoint a Brexit minister to lead the Scottish Government in talks with the UK Government.

However, Ruth Davidson, the Scottish Conservative leader, said Ms Sturgeon was using Brexit to deflect from the “underlying fragility” of the Scottish economy.

She claimed the Government Expenditure and Revenue Scotland (Gers) figures being published on Wednesday had been brought forward from their normal release date to avoid “pre-election scrutiny” next year.

The data, which will show the full scale of the collapse in oil revenues, has been released each March for the last five years.

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The Tories said that if the revenue figures had been issued next March, as expected, that would fall during the parliamentary session and two months before council elections in May.

Ms Davidson added: “The First Minister is in danger of losing the plot completely. Her own government's figures will show that Scotland benefits from a multi-billion Union dividend.

“And yet, in order to revive her independence obsession, she is trying to pretend these facts don't exist.

“Scotland benefits from being a member of the UK, and the UK benefits from our being there. It is time Nicola Sturgeon ended this charade, took her threat of a second independent referendum off the table, and got back to the day job of sorting out the mess her government has made of our public services.”

Alastair Cameron, director of the pro-UK organisation Scotland in Union, said the economic hit caused by Brexit would be far outweighed by the damage caused if Scotland were to leave the UK.

He added: "By rushing out these speculative and selective Brexit figures in a cynical attempt to muddy the waters ahead of the Gers report, Nicola Sturgeon has all but admitted she has no answers to the economic questions about independence.

"While there is evidence that Brexit could harm the Scottish economy, she has failed to recognise this would be vastly outweighed by the damage caused by turning our back on our biggest trading partner - the rest of the UK, a market nearly four times as big.

“Our membership of the UK has protected us from the sharp tax rises and deep spending cuts to our schools and hospitals that would be an inevitable consequence of the fall in oil prices if Scotland had been independent."

Ms Sturgeon claimed at a press conference in Edinburgh that the “old argument” that the UK offered financial security for Scotland no longer held water.

She added: "Brexit will be deeply damaging to Scotland's economy and to our finances.

“I said the morning after the referendum that we would pursue all options, including the option of independence to achieve this, and that remains the case.

"If it turns out simply not to be possible to protect Scotland's interest through the UK, it must be open to the Scottish people to consider afresh, and in this very different context, the question of independence.

“However, I am very clear that we will enter these UK (Brexit) discussions in good faith."

According to the Scottish Government paper, leaving the EU could make European exports more expensive, deter overseas investors, restrict labour, increase skills shortages and reduce productivity.

A spokesman for the UK Government said the real uncertainty for Scotland’s economy was being caused by talk of a second independence referendum.

Meanwhile, Grant Allan, deputy director of the Fraser of Allander Institute at Strathclyde University, said the government’s analysis contained “little that is new”.